freeCodeCamp/guide/english/csharp/linq/first/index.md

title
First

First

Returns the first element that satisfies an optional given condition. If no element is found, throws an InvalidOperationException;

Signature

Enumerable.First<TSource>(IEnumerable<TSource>, Func<TSource, Boolean>)

Example

var fruits = new List<Fruit>() {
    new Fruit() { Id = 1, Name = "Orange",     Color = "Orange", Quantity: 3   },
    new Fruit() { Id = 2, Name = "Strawberry", Color = "Red",    Quantity: 12  },
    new Fruit() { Id = 3, Name = "Grape",      Color = "Purple", Quantity: 25  },
    new Fruit() { Id = 4, Name = "Pineapple",  Color = "Yellow", Quantity: 1   },
    new Fruit() { Id = 5, Name = "Apple",      Color = "Red",    Quantity: 5   },
    new Fruit() { Id = 6, Name = "Mango",      Color = "Yellow", Quantity: 2   }
};

var firstFruit = fruits.First(); // Orange

var firstYellowFruit = fruits.First(f => f.Color == "Yellow"); // Pineapple